In order to smoothly discharge water film between a road surface and a tread surface of a tread portion toward the rear in the rotational direction of the tire, a pneumatic tire comprising a main groove continuously extending in the circumferential direction of the tire is known. In order to improve the drainage performance of the pneumatic tire, it is proposed to increase a groove volume of the main groove.
However, when increasing groove volume of the main groove, there is a tendency that rigidity of the groove bottom of the main groove decreases. Therefore, at grounding of the tire, the groove bottom of the main grooves vibrates, and it vibrates the air flowing through the main groove, thereby generating air-column resonance noise. Therefore, there is a problem that the noise performance is deteriorated. In this way, the drainage performance and the noise performance have a reciprocal relationship, and it is difficult to improve both of these performances in a balanced manner.